Removal of cutting oil from recycled waste magnesium particles generated during vehicle manufacture, washes them using carbon dioxide under high pressure

摘要

The particles are washed or scrubbed with carbon dioxide under high pressure. During this operation the CO2 is in the liquid- or supercritical state. The magnesium particles are centrifuged before washing with CO2, to reduce oil content. Before washing, the particles are briquetted, to both reduce oil content and compact them. After washing with CO2, the particles are melted down and recycled by casting them as new Mg workpieces. Recycling is carried out in a closed circuit in the same factory. The Mg particles are cuttings, especially from turning operations. The waste arises during manufacture of vehicle parts from magnesium alloys. The plant comprises a liquefaction unit for CO2, a wash chamber for the purification process and an evaporator removing CO2 from the wash chamber, for recycle to the liquefaction unit. An independent claim is included for the plant in which the process is carried out.